The Juvenile Diabetes Research Foundation (JDRF) estimates that up to 3 million people in the United States may have Type 1 diabetes. Recent large clinical trials have demonstrated the therapeutic benefits of continuous glucose monitors (CGMs), leading the way to increased availability of insurance reimbursement of these devices. An estimated 50,000 people with diabetes currently use CGMs, but adoption is forecast to grow steadily to 250,000 users as insulin pump users exchange their devices for next generation pumps with integrated CGMs. This represents a $500 million market opportunity. However, currently available CGMs have technical shortcomings that limit both near-term widespread clinical adoption and longer-term progress towards an artificial pancreas. These limitations include inaccuracy in the hypoglycemic range, frequent calibration requirements, and long run-in times. More importantly, the eventual successful commercialization of an artificial pancreas will likely require the use of multiple redundant sensors for safety. There could be substantial advantages associated with the use of a non-enzymatic, redundant sensor in this context, namely, avoidance of common mode failures. GluMetrics is a venture capital-backed company developing the GluCath Intravascular Continuous Glucose Monitoring System (GluCath System). The sensor in this device uses a novel quenched fluorescence chemical mechanism deployed via an optical fiber. The GluCath System is designed for use in critically-ill patients undergoing intensive insulin therapy. Clinical feasibility has been demonstrated in fifty-two healthy volunteer subjects with Type 1 diabetes mellitus for up to 24 h duration. In these studies, the GluCath sensor was placed in a peripheral vein in the arm. The results agreed closely with a reference glucose analyzer with a 7.5% mean absolute relative difference (MARD), 94.7% of results in the clinically accurate A region of the Clarke Error Grid and 95% of results meeting the accuracy criteria of the ISO 15197 standard. The proposed research is to modify the GluCath sensor for use in subcutaneous tissue. The objective of this phase I project is to demonstrate performance of a subcutaneous GluCath sensor in an animal model for 24 h. Subsequent phase II work will include the demonstration of safety and efficacy in extended duration human clinical studies and prototype development of miniaturized optical and electrical components and a suitable automated insertion device. PUBLIC HEALTH RELEVANCE: An estimated 3 million Americans have Type 1 diabetes. Continuous glucose monitors have been shown to provide significant therapeutic advantages, but current enzymatic sensor technologies have had limited clinical adoption and may not be sufficiently accurate for closed loop control. GluMetrics proposes to develop a novel and more accurate non-enzymatic based glucose sensor capable of achieving a high level of clinical accuracy over the entire physiological range (40 to 400 mg/dL), but especially in the hypoglycemic range (<70 mg/dL).